1. Field of the Invention
This invention relates to a stencil printer, and more particularly to a pump for supplying ink to an ink supply roll of a stencil printer.
2. Description of the Related Art
A stencil printer generally comprises a printing drum which is provided with an ink-permeable peripheral wall and an ink supply roll disposed in the peripheral wall. A stencil master is wound around the peripheral wall of the printing drum and printing ink is supplied to the stencil master by the ink supply roll in response to rotation of the printing drum. As a pump for supplying ink to the ink supply roll, there has been employed a piston pump or a plunger pump.
When ultraviolet ray curing ink is used in a stencil printer, curing of the ink at a part where friction by sliding is applied to the ink can cause trouble. When the ink cures, excessive load is applied to the pump and the pump can finally become unworkable. Accordingly, the material of the ink has to be carefully selected.